Basic Usage of Unity for Dependency Injection in MVC 4 Project

First, we need to install Unity Application Block library. If you use NuGet:

PM> install-package Unity.Mvc3

Yes, that is the correct version even for MVC 4 (at least at the time of writing).

Bootstrapper.cs file will be created in the project.

Next, inside Applicaton_Start() in Global.asax.cs, put this code:

Bootstrapper.Initialise();

Then register our components inside BuildUnityContainer() method in Bootstrapper.cs. For example:

        . . .
        container.RegisterType<IColourRepository, ColourRepository>();
        container.RegisterType<IInvoiceRepository, InvoiceRepository>();
        . . .

Calling container.RegisterControllers() in order to register controllers is no longer required in recent version.